29 terms

Harcourt 5th Grade Science CA Chapter 2

Earth's Weather
local winds
Depend on local changes in temperature. Example : at the seashore. During the day, the land heats up more quickly than the water does, so the breezes blow from the sea to the land. But at night, air over the water is warmer than air over the land, so the breezes blow from the land to the sea.
prevailing winds
1. Are global winds that blow constantly from the same direction.
2. Are caused by the uneven heating of large parts of Earth's atmosphere.
air mass
A huge body of air which has the same general properties as the land or water over which it forms.
The border where two air masses meet. They usually don't mix, instead, they form a border called ___________.
1. A very strong storm with a lot of rain, thunder, and lightning. 2. Forms when warm humid air is pushed high into the atmosphere. 3. Water vapor condenses & precipitation occurs. 4. A cold downward air draft "shuts off" storm. 5. Most T storms are over within an hour. 6. They usually occur in late afternoon.
1. is a large spiraling storm (can be up to 372 miles wide). 2. Can last for more than a week. 3. Winds between 75 - 186 miles per hour. 4. Form over warm tropical waters. 5. When reaches land rain & winds are very destructive (floods). 6. Usually die out over land.
tropical storm
A tropical depression, a low-pressure area over an ocean; when the air pressure is low, or "depressed", and winds blow in to the low-pressure area, and the rotation of the Earth causes them to spiral around the low. When the winds reach a constant speed of 39 miles per hour over a tropical depression, this tropical depression is a ____________ ______________.
1. An intense wind storm that usually forms within a severe thunderstorm. 2. Swirling column of air cup to 300 miles per hour.
How does uneven heating of Earth's surface produce wind?
The uneven heating of Earth's surface produces wind because the air temperature and air pressure are different. The differences in the air causes the air to a lower pressure. The movement of this is wind. Uneven heating of the Earth's surface produces air masses of different temperatures. Cold air sinks, forcing warm air to rise.
What causes local winds?
1. During the day, the land heats up faster than the sea. Cooler sea air moves toward the land. This is called a sea breeze.
2. At night, the land loses heat faster than the sea. Cooler air over the land moves toward the sea. This is called a land breeze.
How does prevailing winds affect the weather system in the United States?
It makes weather move west to east.
Suppose you're at the seashore on a sunny summer day. In which direction is the wind blowing? Why?
The direction is probably from the ocean to the land because cold air pushes warm air. The ocean on water changes temperature slower than on land, so the air would go in a circle or direction toward land.
How do the prevailing winds affect weather systems in the United States?
The prevailing winds affect the weather systems in the United States from the west, so weather systems tend to move from west to east.
Shortly after daybreak at the seashore, the air temperate over sea and land is about the same. What sort of wind, if any, is blowing? Explain.
There would be a very slight land breeze, or non at all, because the temperatures are not very different, so there wouldn't be much wind.
The Global Winds map shows
prevailing winds.
A prediction of what the weather will be like in the future.
station model
An arrangement of symbols and numbers that show the weather conditions recorded at a weather station.
surface map
A map that includes station model symbols and information about fronts and about centers of high pressure and low pressure.
weather balloon
A balloon released into the atmosphere that carries a package of instruments to record data about temperature, air pressure, and humidity.
weather map
A map that shows data about recent weather conditions across a large area.
weather relating to High Pressure
Colder weather. Heavy air.
weather relating to Low Pressure
Fair weather. Lighter air.
Tropical depression
A low-pressure area over an ocean. The air pressure is low or "depressed." Winds blow into the low-pressure area, and the rotation of the Earth causes them to spiral around the low.
How does winds blow?
From high to low
What does the uneven heating of Earth's surface cause?
1. Air to be in constant motion (wind). 2. Wind moves based on wire pressure, high and low. 3. Warm air is low; cold air is high
How does warm air move when it meets cold air mass?
The warm air moves over the top of the cold air.
What is a prevailing wind?
1. they are global winds. 3. Help move weather in USA from west to east (westerlies), from California to New York.
How does a cold front form?
It forms when a cold air mass moves in to replace a warm air mass. The colder air mass forces the warmer air up into the atmosphere As the warm air is pushed upward, it cools and forms clouds. Rain develops. Thunderstroms often occur along a cold front.
How does a warm front form?
When a warm air mass moves over a cold air mass. The warm air slides up over the colder, denser air. Clouds form, sometimes many miles ahead of where the front is moving along the ground. Steady rain or snow may fall as the front approaches and passes. Then the sky becomes clear of clouds and the temperature rises.